Upgrading an R4400/200 IP19 to R4400/250
Upgrading an R4400/150 IP19 to R4400/200 or R4400/250
NOTE: The procedures described below have worked for me but don't blame me for any mistakes/errors or catastrophes caused by doing this! It's your responsibility, not mine!!!!
Upgrading an R4400/200 IP19 to R4400/250
What you need:
The images in this section show an R4400/250 IP19 (030-0804-00x) and
were taken by Joerg Gerigk and Reinhard Wolf.
Here's the relevant section from a hinv -v:
CPU Board at Slot 2: (Enabled) Processor 0 at Slot 2/Slice 0: 250 Mhz R4400 with 4 MB secondary cache (Enabled) Processor 1 at Slot 2/Slice 1: 250 Mhz R4400 with 4 MB secondary cache (Enabled) Processor 2 at Slot 2/Slice 2: 250 Mhz R4400 with 4 MB secondary cache (Enabled) Processor 3 at Slot 2/Slice 3: 250 Mhz R4400 with 4 MB secondary cache (Enabled) CPU: MIPS R4400 Processor Chip Revision: 6.0 FPU: MIPS R4000 Floating Point Coprocessor Revision: 0.0This machine was upgraded using the procedure described above on 22nd May 2000 and has been running just fine since then. I have benchmarked it using Ian Mapleson's benchmarks and it has performed all the usual visual simulation stuff without fault (so far).
Also performed the same upgrade to another 4 x R4400/200 on 23rd July 2000. Both boards are running just fine at 250MHz!
Upgrading an R4400/150 IP19 to R4400/200 or R4400/250
Note: You must have a 3.3V CPU board to try this!!!!
Same equipment and procedure as above. Unfortunately, the upgrade doesn't seem to work on the IP19 2 x R4400/150 (030-0374-008) that I have: a PROM exception is generated in the IP19 PROM just after the secondary cache is tested. The machine drops into POD mode and that's that. I'd be interested in hearing about experiences with other R4400/150 IP19s.
Fortunately, the board can be restored by removing the PROMs, jumpers and oscillator and reinstalling the R4400/150 PROMs. The R4400/250 and 200 MHz CPUs seem to behave just fine when underclocked so if you don't feel like replacing them then its probably safe to just leave them.
Contributors without whom this would not have been possible: